Delay tolerant networks and Prophet routing protocol

Abstract

Due to the ubiquitous network connectivity in the modern developed world it is easy to miss the need for networks that would enable communications in environments where network infrastructure is not present. Delay and disruption tolerant networks (DTN) enable communication in such environments as they do not need direct connectivity between nodes that intend to communicate. This diploma presents an overview of an implementation that is intended to show how delay and disruption tolerant networks work; more specifically – it shows how PRoPHET routing protocol could be used on Lego MindStorms robots to demonstrate DTN networks in practice. PRoPHET routing protocol uses the history of encounters amongst network nodes to decide where it should forward the bundles of data. A good way to demonstrate the protocol mechanics is by using Lego MindStorms RCX robots, which are programmed and built in such a way to fulfill the communication and mobility needs. The diploma explores the reasons for existence of the DTN networks and it analyzes problems that are present in the field of DTN routing algorithms. The final implementation consists of a small mobile node and a demonstration platform that can be used to demonstrate the PRoPHET protocol mechanics in real time or analyze it with the use of analysis and logging tools. The results show that it is possible to demonstrate how a DTN network works using the LEGO MindStorms and at the same time uncover some of the issues faced when a DTN network implementation chooses to use the PRoPHET routing protocol. Some of the final conclusions and findings were the basis for further PRoPHET development as a part of the Sami Network Connectivity project. This development resulted in the first DTN network running PRoPHET protocol intended for use by the inhabitants of northern Sweden.